java多線程實現生產者與消費者---經典問題

標籤：

前幾天老師領著學習了一下單線程和多線程的題目。

這裡是作業系統中非常經典的題目，生產者和消費者的題，這裡涉及的是倉庫，

只有一個人（生產者或消費者）進入，另一個人只有等待。

這裡的重點是關於傳值的問題。一定要保持一致，不然，對於存和取 的對象，就可能出現多個。

//========================================================================//

倉庫類

//========================================================================//

package House;


import java.util.ArrayList;
import java.util.List;
import java.util.Random;


public class WareHouse{


ArrayList<Integer>  products = null;

private final int MAXN = 20;
public WareHouse(){
products = new ArrayList<>();
}

public void add(int number){
try {
synchronized (products) {
if(products.size() < MAXN){
System.out.printf("生產者向倉庫中存入了一個編號為%d商品\n", number);
products.add(number);
System.out.printf("倉庫有中共有: "+ products.size() + "個\n");
products.notify();
}else if(products.size() == MAXN){
System.out.println("倉庫已滿，請耐心等待消費者來取走商品！！！");
products.wait();
}
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

public void get(int number){
try {
synchronized (products) {
if(products.size() == 0){
System.out.println("倉庫已空，請耐心等待商品的添加！！");
products.wait();

}else if(products.size() > 0){
System.out.printf("消費者取出了編號為%d的商品\n", products.get(0));
products.remove(0);
System.out.println("倉庫有中共有: "+ products.size() + "個\n");
products.notify();
}
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

//===============================================================//

消費者類：

//==========================================================================//

package House;


import java.util.Random;


public class Customer implements Runnable {
Random ran = new Random();
public WareHouse wa;
public int name;
public Customer(WareHouse wa, int name) {
// TODO Auto-generated constructor stub
this.wa = wa;
this.name = name;
}
@Override
public void run() {
// TODO Auto-generated method stub
for(int i = 0; i < 20; i++){
int getnumber = ran.nextInt(600);
wa.get(getnumber);
}

}


}

//=====================================================================================//

生產者類

//=====================================================================================//

package House;


import java.util.Random;


public class Producer implements Runnable {
Random ran = new Random();
public WareHouse wa;
public int name;

public Producer(WareHouse wa, int name) {
// TODO Auto-generated constructor stub
this.wa = wa;
this.name = name;
}
@Override
public void run() {
// TODO Auto-generated method stub
for(int i = 0; i < 20; i++){
int addnumber = ran.nextInt(500);
wa.add(addnumber);
}

}


}

//======================================================================================//

測試類別

//========================================================================================//

package House;


public class Test {


public static void main(String[] args) {
// TODO Auto-generated method stub

System.out.println("消費者和生產者的大戰開始了----->>>>>>");
WareHouse wa = new WareHouse();
Producer p = new Producer(wa, 1);
Customer C = new Customer(wa, 1);
Thread P1 = new Thread(p);
P1.start();
Thread C1 = new Thread(C);
C1.start();
System.out.println("消費者和生產者的資源搶佔結束----->>>>>>");
}


}

java多線程實現生產者與消費者---經典問題